Low voltage to coils

I'm chasing down what I believe to be an ignition issue. There is no power below 3K RPM. When it is idling I can unplug the coil for cylinders #2 & #3 with no change in engine running. I've swapped coils and the problem remains with whatever coil is firing #2 &#3. I've swapped the pulsing coils from my GPz with no change. I've replaced the primary wires, plugs, etc. The coils are Dyna 2.2 Ohm.
The voltage drop to the coils is about 1.5V. Is this enough to cause one side not to function at low RPMs? If not, my next step is going to be to replace the igniter.

Update: Built a quick coil relay setup and got over 12V to both coils. No change. I can unplug the coil for the #2 #3 cylinders and the engine runs the same.
Sigh... Igniter?

Might have to clean your wire connections, I usually do mine with electrical contact cleaner, steel wool, very fine sandpaper, hopefully that is all it is.

You sure it's not mechanical or fuel related? Adjust valves and compression check? Clean carbs including the pilot circuits and new O-rings throughout?

Nessism wrote: You sure it's not mechanical or fuel related? Adjust valves and compression check? Clean carbs including the pilot circuits and new O-rings throughout?

Hi Nessism, The top end was done last year. Valves were adjusted, carbs were unganged, taken apart and put thru an ultrasonic. Compression is fine. I've swapped in carbs from my GPz and I get the same result. The plugs for 1 and 4 are tan. The plugs for 2 and 3 are dark and sooty.

Not sure but if 2&3 just don't fire regardless then maybe the ignitor like you suspect.

You've swapped the ignition coils & the pickups coils. How about the spark plugs? Have you done the igniter tests outlined in the FSM?
After making sure it isn't the spark plugs, I would make certain the wiring & connections are good. I would remove each wire from the igniter connectors & pulsing coil connector for cleaning & inspection. A terminal pin removal tool is handy.

JMKZHI wrote: You've swapped the ignition coils & the pickups coils. How about the spark plugs? Have you done the igniter tests outlined in the FSM?
After making sure it isn't the spark plugs, I would make certain the wiring & connections are good. I would remove each wire from the igniter connectors & pulsing coil connector for cleaning & inspection. A terminal pin removal tool is handy.

Yes, Spark plugs were swapped. So were the wires. I get a spark from two and three but it seems sporadic and weak. When this first happened I replaced the stock coils with Dynas. Same result.
I went thru the igniter testing in my Clymer manual and it passed but then there is a caveat that says "if the igniter passes these tests you should replace it with a known good one and see if that solves the issue. Some transistorized ignition troubles won't show up on a bench test."
I'll check my connections.
Thanks

In case the clymer has any errors, there should be a KZ750 pdf available that covers your GPz 750. Either here on KZRider or at 750Turbo.com. The Turbo site has 2 different pdfs. One of them is very good with good scans, but the other one is a poorly copied version.

Sorry, should have specified. This is on the KZP.
I have a KZ1000 factory manual I am going thru now. I tested the pickup coil resistance and they are within spec at 402 and 404 ohms.

Checked the voltage from the Igniter 6-pin (red, green and black). Green and black are battery voltage as they should be. Red is only 10.8V.
Voltage from the 4-pin connector are within spec for the red and blue ( .82V) but below for yellow and black (.19V).

The igniter has two circuits. One for 1-and-4 and one for 2-and-3.
You can swap the circuits to see if it's the igniter circuit that is dead.

You swap the big green wire from the 2-3 coil with the big black wire from the 1-4 coil.
Then on the small wires, you swap black with yellow, and swap blue with red.

That makes it so the pickup and coil for cylinders 2 &3 are using the 1-4 igniter circuit, and the pickup and coil for cylinders 1 & 4 are using the 2-3 igniter circuit.
If the 2-3 igniter circuit is bad as suspected, then 2 & 3 will now fire, and 1 & 4 won't.